AC temp while on vacation

[frostola]

What is a good temp to set the thermostat at while on vacation during the summer months?

[dewilson58]

82.

[OpusX1]

When I was a snowbird I would set mine at 87 during the day and 84 at night, that way the ac would always come. On once a day to circulate the air. Never had a mold or mildew problem. This only works if you have a programmable thermostat.

[retiredguy123]

There is a de-humidify setting that will over-cool the temperature setting by about 3 degrees when the humidity is high. So, if you set the temperature to 82, it will cool the house down to 79 only when the humidity goes above the humidity setting.

[anothersteve]

And keep the ceiling fans on low just to keep the air circulating
Steve

[Toymeister]

And keep the ceiling fans on low just to keep the air circulating
Steve

I advise against this. First the enemy of a vacant home is mold. Ceiling fans do not inhibit mold, dry air does.

Your goal is 60% or less.

I have a humidity monitor, anything above 84 routinely trips the alarm.

Second point on the ceiling fans: if you run four at low you will consume 57.6 KwH of electricity. This is a 80% increase in your vampire electricity load. It is simply a waste of money. Use that money to run your ac an extra 23.5 hours in a month.

How do I know this? I have a electricity monitor which checks the draw 10,000 times a second. It has been helpful to discuss or decide the benefits of electricity usage, as well as identify problems.

[anothersteve]

I advise against this. First the enemy of a vacant home is mold. Ceiling fans do not inhibit mold, dry air does.

Your goal is 60% or less.

I have a humidity monitor, anything above 84 routinely trips the alarm.

Second point on the ceiling fans: if you run four at low you will consume 57.6 KwH of electricity. This is a 80% increase in your vampire electricity load. It is simply a waste of money. Use that money to run your ac an extra 23.5 hours in a month.

How do I know this? I have a electricity monitor which checks the draw 10,000 times a second. It has been helpful to discuss or decide the benefits of electricity usage, as well as identify problems.

I had my AC set on 81, with the ceiling fans (3), on low for six months at minimal expense. To each his own.
Steve

[Arctic Fox]

What is a good temp to set the thermostat at while on vacation during the summer months?

Install a humidistat. That way you can set your a/c to 80F and it will only kick in when the humidity is high (which is what causes mold). Leave the fans off.

[HiHoSteveO]

What is a good temp to set the thermostat at while on vacation during the summer months?

Cool "Hold" temp at 82

Humidity 58-60%

No ceiling fans

[rjm1cc]

Low 80's should work. The point of the AC being on is to reduce the humidity in the air and thus reduce the possibility of mold. I have read a few articles on setting the AC to the low 70's from say midnight to 6 am to dehumidify the air. Thus dehumidifying the air once a day.

[Peterriess]

I installed a Nest thermostat. It has a setting called "Cool to Dry". It controls both temp and humidity. So far it has worked like a charm. No mold, mildew or musty odors. Munns did the installation. programed the thermostat and my iPhone for remote setting.

[Aloha1]

Temp set at 80 and ceiling fans on low. Fans help to spread the air and humidity around the room, balancing the temp which means the a/c won't come on as often. We have 2 ceiling fans on our lanai which is enclosed with glass sliders. Temps and humidity can get up pretty high in the summer so those fans stay on 24/7.

[dewilson58]

Temp set at 80 and ceiling fans on low. Fans help to spread the air and humidity around the room, balancing the temp which means the a/c won't come on as often. We have 2 ceiling fans on our lanai which is enclosed with glass sliders. Temps and humidity can get up pretty high in the summer so those fans stay on 24/7.




I've never left fans on when on Vaca........(the OP question)......do you leave them on for weeks at a time when away??

[ColdNoMore]

I leave my thermostat at 83 in summer and the heater at 67 in winter, so that it will hopefully come on at least a few times when I'm gone for more than a few days...but never run the fans.

The way I look at it, there is a finite number of hours on any fan...so why accelerate their demise? :shrug:

[Toymeister]

Temp set at 80 and ceiling fans on low. Fans help to spread the air and humidity around the room, balancing the temp which means the a/c won't come on as often..

With three temp monitors in the home I can assure you that the fans do not balance the temp. From one room to another the temp stays within one degree. I have been observing this remotely for three years. Day after day month after month season after season, one degree.

I can turn on the fans remotely, one degree diff, fans off same results.

[CFrance]

I leave my thermostat at 83 in summer and the heater at 67 in winter, so that it will hopefully come on at least a few times when I'm gone for more than a few days...but never run the fans.

The way I look at it, there is a finite number of hours on any fan...so why accelerate their demise? :shrug:
Plus... I'm afraid of them overheating from being run 24/7 and causing an electrical fire.


We leave our CYV at 84. Neighbors check after storms.

[ColdNoMore]

Plus... I'm afraid of them overheating from being run 24/7 and causing an electrical fire.


We leave our CYV at 84. Neighbors check after storms.

Excellent point! :thumbup:

[Arctic Fox]

What is a good temp to set the thermostat at while on vacation during the summer months?

I hope you weren't relying on a definitive answer - we're not very good at those :icon_wink:

[ColdNoMore]

I hope you weren't relying on a definitive answer - we're not very good at those :icon_wink:

Oh, I don't know about that. :D


Just set it definitely somewhere between 67 and 84 degrees...and maybe even turn on a fan or two. :1rotfl:

[VJBama]

I hope you weren't relying on a definitive answer - we're not very good at those :icon_wink:

It sounds like you have one or two who used the scientific method and have you the answer. The rest are opinions.

[coffeebean]

When we were seasonal residents, we set our humidistat to 60% and set the HVAC to 83 for COOL and 45 for HEAT. We kept the ceiling fans on low. We did that for 9 months a year for 3 years until we moved here full time. The house smelled fresh as a daisy every time we came back after 9 months away.

[tophcfa]

We leave our A/C at 82 and an insurance policy against mold, in case the A/C stops working, we keep a de-humidifier on the kitchen counter which drains into the sink and set it to go on if the humidity in the house reaches 60%. As long as the A/C is working, the de-humidifier should not need to go on. I sleep better knowing we have a back up system to protect against possible mold damage. We don't leave any ceiling fans on.

[UpNorth]

The "Dehum away mode" on my new Honeywell thermostat sets he default position as 60% humidity, 80F Degrees Temp. Always tried to do this with my old thermostat and add-on analog humdistat.

[retiredguy123]

I don't think that a room de-humidifier will have much effect at all on the humidity in the entire house.

[dewilson58]

One "expert" opinion:

Home » FAQs » What is the Recommended Humidity Level for my Home?
What Is The Recommended Humidity For My Home?

Everyone has their own preferences when it comes to what indoor humidity level is most comfortable. In general, a relative humidity level between 35 to 50 percent is ideal for comfort and to prevent microorganism growth.


Ideal Indoor Relative Humidity Levels by Outdoor Temperature

The most comfortable indoor humidity level will vary from one household to the next, depending on personal preferences. In general, this temperature guide will show you where to keep your indoor relative humidity levels to ensure comfort.

Outdoor temperature over 50˚F, indoor humidity levels shouldn’t exceed 50%
Outdoor temperature over 20˚F, indoor humidity levels shouldn’t exceed 40%
Outdoor temperature between 10˚F and 20˚F, indoor humidity levels shouldn’t exceed 35%
Outdoor temperature between 0˚F and 10˚F, indoor humidity levels shouldn’t exceed 30%
Outdoor temperature between -10˚F and 0˚F, indoor humidity levels shouldn’t exceed 25%
Outdoor temperature between -20˚F and -10˚F, indoor humidity levels shouldn’t exceed 20%
Outdoor temperature at -20˚F or lower, indoor humidity levels shouldn’t exceed 15%


Maintaining Ideal Relative Humidity Levels in the Home

The best tools to keeping relative humidity at ideal levels in your home year-round are whole-home humidifiers and dehumidifiers. These systems automatically work with your home’s heating and cooling systems to add or remove moisture from the air. Utilize a humidifier in winter months when air is naturally drier, and a dehumidifier in the summer when air naturally carries more moisture.


Problems with High Humidity Indoors

When humidity levels are high in the home, there is too much moisture. This not only causes discomfort, but can be damaging to your home.

Excess moisture promotes the growth and spread of mold, mildew, fungi, bacteria, and viruses. These contaminants diminish indoor air quality, causing illness, and can also cause damage to your home.
When indoor humidity levels are too high, asthma and allergy sufferers may experience worse or more frequent symptoms.
High humidity indoors causes the home to feel muggy. You may notice visible condensation on windows and walls. Mugginess can leave you feeling hot and uncomfortable, turning up the air conditioning and expending more energy when just an adjustment in humidity levels are required. This causes more energy to be consumed unnecessarily, increasing your energy bills.


Problems Caused by Low Humidity Indoors

Low relative humidity levels indoors cause a host of issues for people and households.

When indoor air is too dry, asthma and allergy symptoms can worsen. Cold and flu viruses may spread more rapidly, and you may be more prone to sinus infections. You may suffer dry skin, chapped lips, and dry air passageways.
Dry air causes your body to feel colder, despite a warm indoor temperature. The dry air pulls moisture from your skin, leaving you colder and forcing you to turn up the temperature to stay comfortable. Therefore, more energy is expended to heat the home, when a boost in humidity could have kept you comfortable for less.
Dry air is damaging to homes. Wood and other building materials, as well as furniture, are robbed of moisture when air is dry. Cracks and damage can occur to flooring, trim, and even framing around windows and doors.


Keep Googling.

[dewilson58]

https://www.buildingsciencesllc.com/sites/default/files/styles/panopoly_image_original/public/healthy-humidity-levels.png?itok=g3EKaOp0

[B-flat]

I installed a Nest thermostat. It has a setting called "Cool to Dry". It controls both temp and humidity. So far it has worked like a charm. No mold, mildew or musty odors. Munns did the installation. programed the thermostat and my iPhone for remote setting.

We had Munn’s install a Nest thermostat too. We check daily via our iPhones the status of the AC. At present we have the AC set to 80. At one time when we had a home in Ocala we set the thermostat to 83 in our absence. I was not aware of the “cool to dry” feature. Thanks for posting that.

[Toymeister]

Dewilson:

Just for kicks I looked at the average monthly humidity that renters chose for the past six months. They can choose whatever temp/humidity that they want. It varied from 53 to 57%. This simple average was 54.5.

Not a large enough sample but interesting that no one wanted 50% or less. Six different couples.

[retiredguy123]

50 percent or less would be difficult to maintain without a whole house dehumidifier, which most houses do not have. But, I wonder about the mold and mildew issue, because the humidity in my garage is usually way higher than 50 percent, and I have never had any mold or mildew in the house or the garage.

[ricthemic]

Worked 40 years in HVAC service up north. So I have a question regarding all these temperature/dehumidifier post.
Question for full timers and snowbirds. Whatever you set your interior controls at for comfort and or to protect your house from mold during six months of Florida high temps and humidity, why isn’t every garage then loaded with mold?

[Toymeister]

Worked 40 years in HVAC service up north. So I have a question regarding all these temperature/dehumidifier post.
Question for full timers and snowbirds. Whatever you set your interior controls at for comfort and or to protect your house from mold during six months of Florida high temps and humidity, why isn’t every garage then loaded with mold?

You need four elements to grow mold. In your garage there isn't food. There is mold spores, humidity, temperature.

In your home you have the food, soap film, natural fibers, paper. If you did not eliminate the humidity you would have mold growing.

Likewise, if you had unsealed drywall on your garage, you would have food (paper). Your garage is painted. Sunlight also kills mold, you do open your garage door frequently.

[tophcfa]

I don't think that a room de-humidifier will have much effect at all on the humidity in the entire house.

In a relatively small two bedroom house it would certainly at least help. Of course, it is not ideal, but it is certainly better than not having one.

[Arctic Fox]

A dehumidifier is a good idea as it is cheaper to run than the a/c (in terms of both electricity and wear & tear) and it should keep the humidity low, which is what is wanted.

[anothersteve]

Isn't a byproduct of a room dehumidifier dry heat? Wouldn't that be counter productive when AC is running?
Steve

[photo1902]

Worked 40 years in HVAC service up north. So I have a question regarding all these temperature/dehumidifier post.
Question for full timers and snowbirds. Whatever you set your interior controls at for comfort and or to protect your house from mold during six months of Florida high temps and humidity, why isn’t every garage then loaded with mold?

For some reason, people move down here then freak out about mold. Venture to say there are hundreds (if not thousands) of homes here that sit vacant for long periods of time, without having any mold issues.

[graciegirl]

The answer we were told years ago is to put your air conditioner on 83 degrees.

[dewilson58]

You need four elements to grow mold. In your garage there isn't food. There is mold spores, humidity, temperature.

In your home you have the food, soap film, natural fibers, paper. If you did not eliminate the humidity you would have mold growing.

Likewise, if you had unsealed drywall on your garage, you would have food (paper). Your garage is painted. Sunlight also kills mold, you do open your garage door frequently.




:boom:

[retiredguy123]

Isn't a byproduct of a room dehumidifier dry heat? Wouldn't that be counter productive when AC is running?
Steve
Yes, a dehumidifier works by cooling the air to remove moisture, and then reheating it back to the original temperature.

[Arctic Fox]

Isn't a byproduct of a room dehumidifier dry heat? Wouldn't that be counter productive when AC is running?

Yes - you wouldn't run both; just the dehumidifier

As long as you don't set the humidity level too low (others here have recommended 50%) then having a hot, dry house shouldn't cause any problems.

[pauld315]

78 if you have wood or laminate floors

[Aloha1]

I've never left fans on when on Vaca........(the OP question)......do you leave them on for weeks at a time when away??

Answer: Yes. My fans are on low constantly all year round whether home or away. Something we learned to do when living in Hawai'i.

[Aloha1]

Worked 40 years in HVAC service up north. So I have a question regarding all these temperature/dehumidifier post.
Question for full timers and snowbirds. Whatever you set your interior controls at for comfort and or to protect your house from mold during six months of Florida high temps and humidity, why isn’t every garage then loaded with mold? :BigApplause:

[Aloha1]

With all due respect to the other posters, the biggest cause of mold is MOISTURE! That's why it's key to keep humidity below 60% here in Florida. Our garages don't get mold because they are concrete block with no drywall. Inside we have drywall which is a food source for mold when combined with high humidity levels. You can certainly keep your home humidity below 50% if you are willing to keep your home at 70 to 72 degrees F all summer long. Personally, I don't like wearing sweaters inside in the summer. All I can say after 21 years of living in Hawai'i and Florida is that I've never had a mold problem, a ceiling fan burn up, or high electric bills by keeping my fans on low and temp set at 81 when away. FYI, when home, we set at 77. In both cases my humidity level never goes above 55-57. My best advice? Get a wi-fi thermostat so you can monitor what's happening when you are away. Adjust accordingly based on YOUR experience.

[B-flat]

Worked 40 years in HVAC service up north. So I have a question regarding all these temperature/dehumidifier post.
Question for full timers and snowbirds. Whatever you set your interior controls at for comfort and or to protect your house from mold during six months of Florida high temps and humidity, why isn’t every garage then loaded with mold?


I’d like to hear this answer to this one too! :)

[retiredguy123]

With all due respect to the other posters, the biggest cause of mold is MOISTURE! That's why it's key to keep humidity below 60% here in Florida. Our garages don't get mold because they are concrete block with no drywall. Inside we have drywall which is a food source for mold when combined with high humidity levels. You can certainly keep your home humidity below 50% if you are willing to keep your home at 70 to 72 degrees F all summer long. Personally, I don't like wearing sweaters inside in the summer. All I can say after 21 years of living in Hawai'i and Florida is that I've never had a mold problem, a ceiling fan burn up, or high electric bills by keeping my fans on low and temp set at 81 when away. FYI, when home, we set at 77. In both cases my humidity level never goes above 55-57. My best advice? Get a wi-fi thermostat so you can monitor what's happening when you are away. Adjust accordingly based on YOUR experience.
My garage, and many other garages do have drywall. I have never had any problem with mold or mildew in the garage.